1. Field of the Invention
This invention relates to novel polymer blends that contain (I) block copolymers of polyphenylene oxides and sterically-hindered aromatic polycarbonates and (II) vinyl aromatic resins. These polymer blends have enhanced physical and/or chemical properties, e.g., enhanced thermal and oxidative product stability. These novel polymer blends can be molded, calendered or extruded as films, sheets, fibers, laminates or other useful articles of manufacture.
2. Description of the Prior Art
Polyphenylene oxide, sterically-hindered aromatic polycarbonate and vinyl aromatic resins are well known in the art.
Illustrative polyphenylene oxide resin descriptions are found in Hay's U.S. Pat. No. 3,306,874 and 3,306,875, White's U.S. Pat. Nos. 4,140,675 and 4,234,706, among others.
Various combinations of polyphenylene oxide resins and vinyl aromatic resins are known such as Cizek's U.S. Pat. No. 3,308,435, Lee's U.S. Pat. Nos. 4,166,055 and 4,166,812, Cooper et al.'s U.S. Pat. No. 4,164,493, Lee's U.S. Pat. No. 4,166,188 and Haaf's U.S. Pat. No. 4,189,411.
Sterically-hindered aromatic polycarbonate resin descriptions are found in Great Britain (General Electric) Pat. No. 1,222,003, Serini et al.'s U.S. Pat. Nos. 3,879,347 and 3,879,348, among others.
Blends of sterically-hindered aromatic polycarbonate and vinyl aromatic resins are described in Serini's U.S. Pat. No. 4,172,103.
Heretofore, polymer blends containing (I) block copolymers of polyphenylene oxides and sterically-hindered aromatic polycarbonates and (II) vinyl aromatic resins have not been reported.
The benefits associated with the compositions of this invention include (1) enhanced oxidative stability, (2) enhanced ultraviolet light stability and (3) improved processing characteristics.